A sure show stopper, the topless Road Runner concept car for 1969 was called Duster I and came fitted with a 426-cubic inch Hemi-head engine that produced a whopping 425 horsepower. Built on a shortened Road Runner platform, the wheelbase was reduced 16-inches to an even 100 inches, and the car rolled on large H60 x 15-inch tires. A built-in roll bar was adjusted to match high-speed racing, and spoilers in the rear quarter panels opened to prevent side-to-side yaw when slipstreaming. Smaller front rock shield spoilers helped to reduce frontal lift.
Source: www.chicagoautoshow.com
Images: Concept Car Central; Custom_Cab's photostream